Andreessen said he wanted to focus more of his time working with start-up companies. He will split his time between working with start-ups and working with AOL on technology issues and potential investments.

"I'm looking forward to my new role, which will allow me to combine my desire to focus more time on getting involved with start-ups with the opportunity to contribute to AOL's future success," he said.

America Online (AOL) acquired rival portal Netscape Communications in November 1998 for $4.2 billion, and as a part of the deal, Andreessen was named CTO in January. His resignation is effective Sept. 13.

Taking over for Andreessen is William J. Raduchel, current chief strategy officer at Sun Microsystems, Inc.(SUNW). In that position, Raduchel was responsible for corporate planning and development, as well as long-range strategy.
At AOL, Raduchel will focus on the company's architecture, technologies and strategic alliances.

"[Bill's] proven abilities at envisioning and forming strategic alliances, and his impressive knowledge of what all businesses need to do to succeed in today's environment, will help us pursue our strategic objectives across the board," said Steve Case, AOL's chairman and chief executive officer.

Raduchel joined Sun in 1988 and held several other positions, including chief financial officer and chief information officer.